We propose to aerosolize delta 9-THC in a propylene glycol and water vehicle and to study its interaction with various bronchoconstricting and bronchodilating agents in normal and asthmatic subjects. We will also study the effect of a usual marihuana cigarette on the EEG as well as its interaction with clinical doses of alpha agents and alpha blocker in terms of attention performance tasks, subjective effect and urinary excretion of catecholamines.